2011-01-03 22:15:20Basic rebuttal 83: Ice isn't melting - VERSION 2
James Wight

jameswight@southernphone.com...
112.213.166.150

This is the original version. See below for the current revision.

I started writing this basic rebuttal months ago but forgot about it. The reason why it’s taken so long is I didn’t think it was basic enough, but I couldn’t decide what information to cut out. Anyway, long story short, here it is. Let me know what you think.

I’d like feedback on a few points in particular:

  • I know the bit about ice shelves isn’t in the intermediate version, but it seems worth mentioning.
  • I also spend a lot more time on Arctic sea ice than the intermediate rebuttal, because I think it’s important.
  • Let me know if you think I’m being alarmist about Arctic sea ice.
  • I wanted to include some info about the impacts of melting ice, but couldn’t fit it in. I decided to focus on saying that ice is melting.

Note to John: For the basic summary, I’ve replaced the existing motherhood statement (“Ice is melting at an accelerating rate at both poles and in glaciers all over the world.”) with the most striking facts (“Arctic sea ice has shrunk by an area equal to Western Australia, and could be all gone in a decade”). Let me know if you’re not happy with this change.


 

The skeptic argument: Ice isn’t melting

What the science says: Arctic sea ice has shrunk by an area equal to Western Australia, and could be all gone in a decade.

Ice is melting at accelerating rates in the Arctic, Antarctica, Greenland, and glaciers all over the world.

Ice sheets are beginning to shrink

An ice sheet is a huge layer of land ice. The only ice sheets existing on present-day Earth are in Antarctica and Greenland. Antarctica is basically divided into two distinct ice sheets, the West Antarctic and East Antarctic. The GRACE satellites launched in 2002 are able to measure gravity so sensitively they can detect changes in the mass of ice sheets.

According to GRACE, the Greenland ice sheet is losing mass at an accelerating rate, doubling between 2002 and 2009. During that time Greenland’s ice loss has spread from the south coast around to the northwest.

Similarly, GRACE has found that Antarctica is also losing ice at an accelerating rate. The East Antarctic ice sheet, which is much bigger than the West Antarctic one, was until recently considered stable, but has also begun losing ice.

Ice shelves are collapsing

Ice shelves are thick, floating platforms of ice formed when glaciers flow from the land onto the ocean surface. In 1978, John Mercer identified the collapse of ice shelves on the Antarctic Peninsula as a warning sign of dangerous warming in West Antarctica.

Fast-forward three decades and the Antarctic Peninsula is warming rapidly. Several ice shelves have collapsed completely, including one covering 3,250 km2, almost twice the area of urban Sydney.

Glaciers are retreating

Glaciers are retreating around the globe. Although one can point to particular glaciers that are growing, glaciologists look for trends in the total mass of glaciers worldwide. It turns out the world’s glaciers are losing ice at an accelerating rate.

And despite all the hype about a certain mistake in the 2007 IPCC report, the Himalayan glaciers are in fact melting.

Southern sea ice not doing much

Sea ice floats on the ocean surface, and is not to be confused with ice sheets on land. Even though the Antarctic ice sheet is losing mass, the extent of sea ice around the coast of the continent has grown slightly.

This is because of a complex variety of factors, and despite the warming of the Southern Ocean. The trend is expected to reverse in coming decades as the Antarctic continues to warm.

Arctic sea ice in a death spiral?

Arctic sea ice grows and shrinks seasonally, with an annual minimum in September. In 1979, when satellites first measured it, September Arctic sea ice extent was roughly equivalent to the area of Australia. Since then it has declined by about a third, equivalent to losing Western Australia – outstripping all projections.

2010 had the third lowest minimum on record (after 2007 and 2008), and two expeditions successfully circumnavigated the Arctic Ocean in a single summer, something that would have been impossible just a few years earlier.

Contrarians claim Arctic sea ice has “recovered” since the record low extent of 2007. But sea ice exists in three dimensions, and it has continued to thin rapidly. Ice volume data paints a picture even more dire: the Arctic has actually lost not one third but two thirds of September sea ice. What’s more, the volume reached a record low in 2010 – not an encouraging sign of recovery.

2010 set the stage for continued melting. At the end of the summer, a record-breaking 86% of ice cover was less than two years old; ice older than five years has all but disappeared. The remaining new ice is thinner and much easier to melt than older ice.

Ice-free summers are now probably inevitable, but it’s not clear how soon because the Arctic is melting much faster than any model predicted. Mark Serreze, Director of the US National Snow and Ice Data Center, says we’re “looking at a seasonally ice-free Arctic in twenty to thirty years.” A few scientists argue that September sea ice could be essentially gone within the next decade.

2011-01-05 15:49:08Bump
James Wight

jameswight@southernphone.com...
112.213.166.150
Any feedback?
2011-01-05 18:35:35
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.207.237

James, I know the feeling (cut to scene of tumbleweeds rolling through a dusty landscape)

Why not assemble all those graphs of declining ice loss, Greenland, Arctic summer sea ice, world glaciers etc. into a single rebuttal?. A sentence or two (with links) explaining the most recent data should suffice. For Antarctic sea ice - point out it is Winter sea ice, with brief explanation & link. Be a very compelling rebuttal I reckon.

2011-01-07 02:08:08
Anne-Marie Blackburn
Anne-Marie Blackburn
bioluminescence@hotmail.co...
212.139.85.64
Very thorough rebuttal - good to explain the differences between ice shelves, ice sheets and other ice bodies.  I think it would certainly benefit from the use of graphs - an image that has stuck to my mind is that of the spread of Greenland's ice loss, for example. It's visually very effective and may convey the message better than words. Though that's only my opinion, and I tend to be visual.
2011-01-07 13:29:40
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
68.188.192.170

You may want to consider adding a bit from this:

http://www.denmark.dk/en/servicemenu/News/Environment-Energy-Climate-News/MeltdownInGreenlandInlandIceDripsAwayAtRecordSpeed.htm

The Danish research scientist Sebastian Mernild of Los Alamos National Laboratory in the US told national daily newspaper Jyllands-Posten that his calculations show that 540 cubic kilometres of inland ice, weighing approx. 500 gigatons, have melted this summer, which is 25-50% more than in a typical year. 

"It is my assessment that we have had the strongest melting since they started measuring the temperature in Greenland in 1873," he said. 

To make that 540 cubic kilometers relatable, that's approximately the volume of Lake Erie.  It is also equivalent to the rise in atmospheric water vapor of the past 30 years due to global warming...

 

2011-01-07 18:46:58Candidate graphs
James Wight

jameswight@southernphone.com...
112.213.166.150

I thought about putting in graphs, but I thought they might be too technical and my post was long enough already. Anyway, here are some candidates. Which ones do you think I should use? (Daniel, do you know of any graph that includes the 2010 Greenland ice loss you mention?)

 

 

 

 


 

2011-01-08 06:06:49
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.225.166

James, what I was suggesting was to let the graphs do the talking. Only minimal explanation & provide links. Don't feel that all the points in your original draft, GRACE for instance, need to be covered. 

An uninformed reader will look at the graphs of arctic sea ice extent, sea ice volume, Greenland ice, Antarctic ice and world glacier ice and think "WTF are those skeptics on about?". I just see it as an opportunity to use some very, very powerful images. 

2011-01-08 08:03:44
nealjking

nealjking@gmail...
91.33.99.72

Rob,

Be careful: For most people, graphs without explanation convey nothing. You generally need to tell people what conclusion they're supposed to get from the graph: THEN it becomes clear.

2011-01-08 09:40:35
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.218.138
Neal, that's not what I was suggesting (although good that you point this out) . A brief explanation of what each graph is showing is all that is required. 
2011-01-12 11:26:07
k9

nick@kocharhook...
84.9.39.213

The first three images you propose only have 7 years of data in them. It seems likely that this is because we only have data from these sources going back that far, but in other places on the site we point out that the skeptics are using cherry-picked data of 10 year durations to support a conclusion which the longer-term trend doesn't support.

See for example: http://www.skepticalscience.com/global-cooling-january-2007-to-january-2008.htm

If you do use any of those three graphs, you might want to explain why we only have 7 years of data, and also include other, longer-term graphs. 

2011-01-13 00:35:30
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
68.188.192.170

Updated version from GRACE for Greenland (source: http://climatesignals.org/2010/10/greenland-ice-now-melting-twice-as-fast/ ):

 

While all of those graphs are compelling and tell a powerful story, my fav is number 6, the Arctic Ice Extent (models and observations).  Not only does it show the decline in the Arctic sea ice, but it clearly shows the underestimation of the trend beyond the accepted understanding of the physical processes involved.  Coupled with the next-to-last chart, that'll cover the Arctic well.

The Glacier change graph is needful, but you will have to indicate how representative it is.  a current meme is that only 100 of 100,000 glaciers worldwide are monitored...

The Antarctic mass-loss graphic with the silhouette of Antarctica on it is the better of the two.  Visually one can see at a glance which pole is being discussed.  Add in some verbage to cover the GRACE issues widely discussed elsewhere & it's a go.

 

Nice job!

2011-01-13 18:10:06Revised version with graphics
James Wight

jameswight@southernphone.com...
112.213.154.212

I've added lots of graphs as many of you suggested. I haven't included an animation of Greenland ice loss because I thought it might just confuse people.

I've also simplified some of the wording and removed some info. Most notably, I no longer mention that the ice sheet measurements come from GRACE, because I decided the basic version probably doesn't need to go into the issues with the measurements - perhaps something about that could be added to the intermediate rebuttal?

K9, are you aware of any easy-to-understand graphs of Greenland or Antarctic ice sheet mass which go back further? The only ones I can remember seeing are a maze of error bars which would probably be incomprehensible to a layperson.


The skeptic argument: Ice isn’t melting

What the science says: Arctic sea ice has shrunk by an area equal to Western Australia, and could be all gone in a decade.

Ice is melting at accelerating rates in the Arctic, Antarctica, Greenland, and glaciers all over the world.

Ice sheets are beginning to shrink

An ice sheet is a huge layer of land ice. The only ice sheets are in Antarctica and Greenland.

The Greenland ice sheet is losing mass at an accelerating rate. In recent years the ice loss has spread from the south coast around to the northwest.

(Image source: Climate Signals.)

Similarly, Antarctica is also losing ice at an accelerating rate. Antarctica is basically divided into two distinct ice sheets, the West Antarctic and East Antarctic. The East Antarctic ice sheet, which is much bigger than the West Antarctic one, was until recently considered stable, but has also begun losing ice.

(Image source: NASA.)

Ice shelves are collapsing

Ice shelves are thick, floating platforms of ice formed when glaciers flow from the land onto the ocean surface.

The Antarctic Peninsula is warming rapidly. Several ice shelves have collapsed completely, including one covering 3,250 km2, almost twice the area of urban Sydney.

 

(Image source: National Snow and Ice Data Center.)

Glaciers are retreating

Glaciers are retreating around the globe. Although one can point to particular glaciers that are growing, glaciologists look for trends in the total mass of glaciers worldwide. It turns out the world’s glaciers are losing ice at an accelerating rate.


(Image data source: Cogley 2009.)

And despite all the hype about a certain mistake in the 2007 IPCC report, the Himalayan glaciers are in fact melting.

Southern sea ice not doing much

Sea ice floats on the ocean surface, and is not to be confused with ice sheets on land. Even though the Antarctic ice sheet is losing mass, the extent of sea ice around the coast of the continent has grown slightly.

This is because of a complex variety of factors, and despite the warming of the Southern Ocean. The trend is expected to reverse in coming decades as the Antarctic continues to warm.

Arctic sea ice in a death spiral?

Arctic sea ice grows and shrinks seasonally, with an annual minimum in September. In 1979, when satellites first measured it, September Arctic sea ice extent was roughly equivalent to the area of Australia. Since then it has declined by about a third, equivalent to losing Western Australia – outstripping all projections.


(Image source: Copenhagen Diagnosis.)

2010 had the third lowest minimum on record (after 2007 and 2008). Two expeditions successfully circumnavigated the Arctic Ocean in a single summer, something that would have been impossible just a few years earlier or any time in recorded history.

Contrarians claim Arctic sea ice has “recovered” since the record low extent of 2007. But sea ice exists in three dimensions, and it has continued to thin rapidly. Ice volume data paints a picture even more dire: the Arctic has actually lost not one third but two thirds of September sea ice. What’s more, the volume reached a record low in 2010 – not an encouraging sign of recovery.

2010 set the stage for continued melting. At the end of the summer, a record-breaking 86% of ice cover was less than two years old; ice older than five years has all but disappeared. The remaining new ice is thinner and much easier to melt than older ice.


(Image source: National Snow and Ice Data Center.)

Ice-free summers are now probably inevitable, but it’s not clear how soon because the Arctic is melting much faster than any model predicted. Mark Serreze, Director of the US National Snow and Ice Data Center, says we’re “looking at a seasonally ice-free Arctic in twenty to thirty years.” A few scientists argue that September sea ice could be essentially gone within the next decade.

2011-01-13 18:25:31
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.67.12
Thumbs up from me.
2011-01-16 01:16:31Attention John Cook
James Wight

jameswight@southernphone.com...
112.213.154.212
Do you mind that I've changed the one-line summary to read "Arctic sea ice has shrunk by an area equal to Western Australia, and could be all gone in a decade"? If not I'll go ahead and paste this into the rebuttal form.
2011-01-16 01:54:52Here's mine
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
68.188.192.170
Looks good!
2011-01-19 04:05:07Looks good
Robert Way

robert_way19@hotmail...
134.153.163.105
James I think it looks great but I do have one suggestion regarding the ice shelves one.

http://www.the-cryosphere.net/4/77/2010/tc-4-77-2010.pdf

You could perhaps take a couple images from there include the most recent wilkins one. My thought is that showing multiple ice shelves including more recent ones might be better than just larsen which has appeared everywhere. You can take that suggestion or not. Good job.
2011-01-20 00:10:10Ice shelves
James Wight

jameswight@southernphone.com...
112.213.154.212

Thanks Robert, but I think I’ll stick with the Larsen B animation I’ve already got. I think it’s more graphic.

2011-01-20 07:35:07
Glenn Tamblyn

glenn@thefoodgallery.com...
124.181.142.191

James. Looks really good.

2 points since this is a basic rebuttal.

A very brief explanation of the seasonal cycle in the Arctic so the significance of the September time frame is conveyed

And perhaps a small expansion on the significance of 1 vs 2 vs multi year ice. Perhaps that what matters is area/extent, volume and quality. I recall reading reports that even the multi-year ice is pockmarked with polynya's that have frozen over with 1st year ice, weakening it - ice structural breakup being a major contributor to loss.

2011-01-22 00:03:31
Paul D

chillcast@googlemail...
82.18.130.183
Ooooooo kkkkkkkkk
2011-02-04 23:35:58
James Wight

jameswight@southernphone.com...
112.213.148.195

I have updated the Greenland graph with the latest GRACE data.

Five thumbs now – John, is this one ready to go live?

2011-02-16 13:48:38Finally published!
John Cook

john@skepticalscience...
144.131.205.143
Sorry took so long to get this one up, James. Thanks, great overview, very useful resource